The DNR manages water quality through the implementation of the state's Water Quality Standards. These standards are found in Chapter 61 of the Iowa Administrative Code. The States Water Quality Standards help ensure that all Iowans have surface waters that are fishable and swimmable to the fullest extent practicable, safe drinking water, groundwater that is free from harmful contamination, protection from the adverse effects of floods, and water resources that are put to their best beneficial uses.

Copper Criteria Update

The DNR is updating the copper criteria for aquatic life protection. The
purpose of the proposed rule is to create additional flexibility for
wastewater dischargers by adding the option to use the Biotic Ligand
Model (BLM) to determine copper water quality criteria or to use the
Water-Effect Ratio (WER) to adjust the existing copper water quality
criteria. Following are the documents associated with this proposal:

Antidegradation refers to federal regulations designed to maintain and protect high quality waters and existing water quality in other waters from unnecessary pollution. For further information please visit the
Antidegradation web page.

Under Iowa's Water Quality Standards it is presumed that all perennial streams and rivers are attaining the highest level of recreation and aquatic life uses and should be protected for activities such as fishing and swimming. A Use Assessment and Use Attainability Analysis (UA/UAA) is a process of gathering field data and assessing the available information to determine if a stream is capable of supporting the highest level of recreation and aquatic life uses, and if not assign a more appropriate recreational and aquatic life use classification.

Help us assess Iowa's streams: take the survey
The DNR is asking for your input on how you recreate in Iowa's streams as we complete recreational assessments on streams in the state. Please
take our online survey to list the streams you use, what activities you use them for and where you access the streams. The DNR will factor the results from the survey into its decision making for applying recreation-based stream designations to Iowa's waters. These assessments are part of classifying recreational stream uses in the state, and will help determine the appropriate level of protection for the stream.

Iowa’s chemical criteria includes both numerical criteria listed in
61.3(3) Table 1 and General Water Quality Criteria described in 61.3(2). Numerical criteria apply to designated waters and general water quality criteria are applicable to all surface waters including general use and designated use waters. The following documents share information about specific criteria.

Under the Clean Water Act, a state shall from time-to-time hold public meetings for the purpose of reviewing applicable water quality standards and, as appropriate, modifying and adopting standards. See
Chapter 61: Water Quality Standards. This review includes, but is not necessarily limited to: Designated Uses, Criteria, and Antidegradation.

Linked below are documents relating to the current Triennial Review for Iowa's water quality standards.